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Validation of climate model-inferred regional temperature change for late-glacial Europe.

Heiri O, Brooks SJ, Renssen H, Bedford A, Hazekamp M, Ilyashuk B, Jeffers ES, Lang B, Kirilova E, Kuiper S, Millet L, Samartin S, Toth M, Verbruggen F, Watson JE, van Asch N, Lammertsma E, Amon L, Birks HH, Birks HJ, Mortensen MF, Hoek WZ, Magyari E, Muñoz Sobrino C, Seppä H, Tinner W, Tonkov S, Veski S, Lotter AF - Nat Commun (2014)

Bottom Line: However, standardized palaeoclimate data sets for assessing the spatial pattern of past climatic change across continents are lacking for some of the most dynamic episodes of Earth's recent past.Here we present a new chironomid-based palaeotemperature dataset designed to assess climate model hindcasts of regional summer temperature change in Europe during the late-glacial and early Holocene.However, ECHAM-4 infers larger amplitudes of change and higher temperatures during warm phases than our palaeotemperature estimates, suggesting that this and similar models may overestimate past and potentially also future summer temperature changes in Europe.

View Article: PubMed Central - PubMed

Affiliation: Palaeoecology, Institute of Plant Sciences and Oeschger Centre for Climate Change Research, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland.

ABSTRACT
Comparisons of climate model hindcasts with independent proxy data are essential for assessing model performance in non-analogue situations. However, standardized palaeoclimate data sets for assessing the spatial pattern of past climatic change across continents are lacking for some of the most dynamic episodes of Earth's recent past. Here we present a new chironomid-based palaeotemperature dataset designed to assess climate model hindcasts of regional summer temperature change in Europe during the late-glacial and early Holocene. Latitudinal and longitudinal patterns of inferred temperature change are in excellent agreement with simulations by the ECHAM-4 model, implying that atmospheric general circulation models like ECHAM-4 can successfully predict regionally diverging temperature trends in Europe, even when conditions differ significantly from present. However, ECHAM-4 infers larger amplitudes of change and higher temperatures during warm phases than our palaeotemperature estimates, suggesting that this and similar models may overestimate past and potentially also future summer temperature changes in Europe.

No MeSH data available.


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Latitudinal changes in July temperature across Europe.(A) EH (~11.4 ka BP, dark blue) compared with modern temperatures (brown); (B) EH compared with YD (~12.0 ka BP, red); (C) EH compared with late BA-IS (~13.0 ka BP, orange); (D) EH compared with early BA-IS (~14.45 ka BP, green); (E) EH compared with ELG (~14.9 ka BP, light blue); (F) YD compared with ELG. Inferred temperatures are adjusted to modern sea level.
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Figure 3: Latitudinal changes in July temperature across Europe.(A) EH (~11.4 ka BP, dark blue) compared with modern temperatures (brown); (B) EH compared with YD (~12.0 ka BP, red); (C) EH compared with late BA-IS (~13.0 ka BP, orange); (D) EH compared with early BA-IS (~14.45 ka BP, green); (E) EH compared with ELG (~14.9 ka BP, light blue); (F) YD compared with ELG. Inferred temperatures are adjusted to modern sea level.

Mentions: All the major climatic transitions in the interval studied at ~14.6, ~12.7 and ~11.7 ka BP are apparent in the stacked reconstructions (Fig. 2). At similar latitudes, chironomid-inferred temperature variations tend to be most pronounced in western Europe (British Isles, southwestern Europe) and more muted in the east (central and southeastern sectors, Fig. 2). Stacked records from western Europe and the Baltic indicate that temperatures during the early Holocene (EH) were similar to those during the BA-IS (Fig. 2). Elsewhere, EH temperatures were warmer than during the BA-IS. We compared latitudinal temperature gradients across Europe for the time slices ~11.4, ~12.0, ~13.0, ~14.45, and ~14.9 ka BP, representing the EH, YD, late BA-IS, early BA-IS, and early late-glacial just preceding the BA-IS (ELG), respectively (Fig. 3). EH temperatures (Fig. 3A) were overall slightly cooler than today, but showed a similar latitudinal summer temperature gradient to that at present (~0.5°C per degree latitude). EH and BA-IS (Fig. 3C-D) latitudinal temperature gradients resembled each other, although in the BA-IS temperatures were slightly lower than in the EH, especially to the north. YD summer temperatures were characterized by a very steep temperature gradient ~48-53°N (Fig. 3B). Temperatures were, on average, 5.9°C below present values north of 52°N, but only 3.5°C lower south of 52°N. ELG temperatures north of ~52°N were similar to YD temperatures (average difference 0.2°C, Fig. 3F). To the south ELG temperatures were clearly lower than YD temperatures (average difference 2.6°C). Reconstructed temperatures in the early BA-IS were cooler than in the late BA-IS east of 10°E, but similar to or higher than late BA-IS temperatures west of 10°E (Fig. 4).


Validation of climate model-inferred regional temperature change for late-glacial Europe.

Heiri O, Brooks SJ, Renssen H, Bedford A, Hazekamp M, Ilyashuk B, Jeffers ES, Lang B, Kirilova E, Kuiper S, Millet L, Samartin S, Toth M, Verbruggen F, Watson JE, van Asch N, Lammertsma E, Amon L, Birks HH, Birks HJ, Mortensen MF, Hoek WZ, Magyari E, Muñoz Sobrino C, Seppä H, Tinner W, Tonkov S, Veski S, Lotter AF - Nat Commun (2014)

Latitudinal changes in July temperature across Europe.(A) EH (~11.4 ka BP, dark blue) compared with modern temperatures (brown); (B) EH compared with YD (~12.0 ka BP, red); (C) EH compared with late BA-IS (~13.0 ka BP, orange); (D) EH compared with early BA-IS (~14.45 ka BP, green); (E) EH compared with ELG (~14.9 ka BP, light blue); (F) YD compared with ELG. Inferred temperatures are adjusted to modern sea level.
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Related In: Results  -  Collection

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Figure 3: Latitudinal changes in July temperature across Europe.(A) EH (~11.4 ka BP, dark blue) compared with modern temperatures (brown); (B) EH compared with YD (~12.0 ka BP, red); (C) EH compared with late BA-IS (~13.0 ka BP, orange); (D) EH compared with early BA-IS (~14.45 ka BP, green); (E) EH compared with ELG (~14.9 ka BP, light blue); (F) YD compared with ELG. Inferred temperatures are adjusted to modern sea level.
Mentions: All the major climatic transitions in the interval studied at ~14.6, ~12.7 and ~11.7 ka BP are apparent in the stacked reconstructions (Fig. 2). At similar latitudes, chironomid-inferred temperature variations tend to be most pronounced in western Europe (British Isles, southwestern Europe) and more muted in the east (central and southeastern sectors, Fig. 2). Stacked records from western Europe and the Baltic indicate that temperatures during the early Holocene (EH) were similar to those during the BA-IS (Fig. 2). Elsewhere, EH temperatures were warmer than during the BA-IS. We compared latitudinal temperature gradients across Europe for the time slices ~11.4, ~12.0, ~13.0, ~14.45, and ~14.9 ka BP, representing the EH, YD, late BA-IS, early BA-IS, and early late-glacial just preceding the BA-IS (ELG), respectively (Fig. 3). EH temperatures (Fig. 3A) were overall slightly cooler than today, but showed a similar latitudinal summer temperature gradient to that at present (~0.5°C per degree latitude). EH and BA-IS (Fig. 3C-D) latitudinal temperature gradients resembled each other, although in the BA-IS temperatures were slightly lower than in the EH, especially to the north. YD summer temperatures were characterized by a very steep temperature gradient ~48-53°N (Fig. 3B). Temperatures were, on average, 5.9°C below present values north of 52°N, but only 3.5°C lower south of 52°N. ELG temperatures north of ~52°N were similar to YD temperatures (average difference 0.2°C, Fig. 3F). To the south ELG temperatures were clearly lower than YD temperatures (average difference 2.6°C). Reconstructed temperatures in the early BA-IS were cooler than in the late BA-IS east of 10°E, but similar to or higher than late BA-IS temperatures west of 10°E (Fig. 4).

Bottom Line: However, standardized palaeoclimate data sets for assessing the spatial pattern of past climatic change across continents are lacking for some of the most dynamic episodes of Earth's recent past.Here we present a new chironomid-based palaeotemperature dataset designed to assess climate model hindcasts of regional summer temperature change in Europe during the late-glacial and early Holocene.However, ECHAM-4 infers larger amplitudes of change and higher temperatures during warm phases than our palaeotemperature estimates, suggesting that this and similar models may overestimate past and potentially also future summer temperature changes in Europe.

View Article: PubMed Central - PubMed

Affiliation: Palaeoecology, Institute of Plant Sciences and Oeschger Centre for Climate Change Research, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland.

ABSTRACT
Comparisons of climate model hindcasts with independent proxy data are essential for assessing model performance in non-analogue situations. However, standardized palaeoclimate data sets for assessing the spatial pattern of past climatic change across continents are lacking for some of the most dynamic episodes of Earth's recent past. Here we present a new chironomid-based palaeotemperature dataset designed to assess climate model hindcasts of regional summer temperature change in Europe during the late-glacial and early Holocene. Latitudinal and longitudinal patterns of inferred temperature change are in excellent agreement with simulations by the ECHAM-4 model, implying that atmospheric general circulation models like ECHAM-4 can successfully predict regionally diverging temperature trends in Europe, even when conditions differ significantly from present. However, ECHAM-4 infers larger amplitudes of change and higher temperatures during warm phases than our palaeotemperature estimates, suggesting that this and similar models may overestimate past and potentially also future summer temperature changes in Europe.

No MeSH data available.


Related in: MedlinePlus